R: [DB2-L] DB2 z/OS V8 - Unit switch performance figures

Mauro Moschelli

R: [DB2-L] DB2 z/OS V8 - Unit switch performance figures
Do you use IBM or 3rd party utilities to load data?
Some (perhaps most or all) 3rd party utilities stop the tablespace to
complete the load, so the object is closed.



Mauro Moschelli
Intesa Sanpaolo S.p.A.

IBM Certified Database Administrator - DB2 UDB V8.1 for z/OS


-----Messaggio originale-----
Da: DB2 Data Base Discussion List [mailto:[login to unmask email]Per conto
di [login to unmask email]
Inviato: giovedì 13 dicembre 2007 14.45
A: [login to unmask email]
Oggetto: Re: [DB2-L] DB2 z/OS V8 - Unit switch performance figures





Hi Avram

Answers below, thanks.

New Application in New DB2
We belive the page spaces were opened prior to the begining of the test
because ____________?

The number of currently/max open datasets doesn't change during the
test.


Discribe your test preperation procedure. Do you recover the
tablespaces and
rebuild indexes?
Data is loaded with replace to all test tables (897 tables).

You say everything is defined as CLOSE=NO (not the current popular
recomendaton) Does this include EVERYTHING including system objects?
temp
and work space?
I haven't checked the system/temp tables, but all test tablespaces and
indexes have CLOSE NO.

Is this member part of a datasharing group (even single member data
sharing)?
It is part of a 2 system data sharing group, with the test coming from
both sides.

Regards
Avram Friedmna

On Thu, 13 Dec 2007 10:02:13 +0000, [login to unmask email] wrote:

We have been stress testing a new application in a new DB2 environment,
and , according to Mainview, we are seeing very high values for Unit
Switch
Open/Close, see below for an example where 11 seconds was spent in Open/

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